Improved furnace for roasting- and calcining ores



dlrtrd rms- @atrd @Mira ERNST WEs'rMAN, OF STOCKHOLM, SWEDEN. f

Letters Patent No. 85,881, dated January 12, 1869.

IMPRCVED FURNACE FOR ROASTING AND CALCINING- CRES.

The Schedule referred to in -these Letters Patent and making part of the same.

Toh alZVwho/mtt may concern: i

Be it known that I, ERNST WESTMAN, of Stock- 1l1olm, in the Kingdom of Sweden, have invented a new and improved Furnace for Roasting and Calcining Ores; vand I do hereby declare that the following is a full,

clear, and exact description thereof, which will enable 'others skilled in the art to make aud use the same,

reference being had to the accompanying drawings,

' forming part of this specification.

Figure 1 represents a sectional elevation of .my im- Figures 2, 3, 4, and 5, are 'horizontal sections of the same, taken on the planes of the lines marked thereon. Figure 6 is a det-ail vertical section'of a chimney, of modified construction.

Figure 7 is a horizontalsectiou of the same. Similar letters of reference indicate corresponding arts. p This invention relatesto a new furnace for roasting fand calcining ores, by'meanvs of gases that are`produced by the combustion of suitable fuel; and

The invention consists in such an arrangement of 4 parts that ore of suitable quality can be perfectly freed This gate or shutter p has an outward-projecting' arm or arms,'as shown.

The ore to be roasted is elevated in a cart or truck, that is suspended from a rope passing over a pulley, fr, the truck running on an elevated track, B.

Y When the truck is almost quite elevated, itl strikes against the projecting arm of the shutter p, and swings the same around its pivot t, so'as to open it.

The truck is then overturned, and discharges its load into the mouth b, upon an inclined plane, s.

The ore falls from the mouth l1 into a funnel, c, by which it is collected and guided into the centre of the furnace.

The funnel is, however, movable, being attached to a sliding handle, as shown, so as to guide the ore to any desired part of the furnace.'

Through the opening al, the interior of the furnace canrbe inspected, to ascertain if the furnace has been lled with ore. f l

Through the pipesA e, which are connected with each other all around the furnace, communicating, through the small tubes g, with the interior of the furnace, gas,

from a suitable dame, is introduced, which is received either from the blast-furnace or from a special gas- 'generator, its quality' depending upon Ithe description offilel required to be used. A

The iron 'supports f, serving to support the lining of the shaft, are provided with small tuyeres, and communicate with the conducting-pipes h, through which the compressed air (blast) is introduced.

l i are openings for removing the roasted ore, and

kl m are working-holes. v

n is the chimney, provided at lthe top with a damper for regulating the draught.

It can be constructed either,.as in fig. 1, of brickwork, or, as in 6 and 7, of cast-iron and plates.

In using ores which can beeasily roasted, the chimney, as well as the blast, may be dispensed with, although it always facilitates the management of the furnace and the regulation of the draught.

Through the small apertures o o, the state of the interior of the furnace can be observed, so that the heat and the removal oi' the ore can be regulated ac-v cordingly.

The process is as follows:

When the furnace has been charged with ore up to the line Y Z, and heated,` gasisv forced in through the tubee, which can be regulated partly by means of a valve inthe main tube, partly by small sliding castiron dampers in the holes k.

The gas entering into the furnace, is met by' and combusted by air, partly from theblast-pipe h, partly from the openings t i.

The ore, which thus gets more and more heated, is removed through the openings 'i t, after having previously reached almost meltingheat, so that it requires to be worked, and broken, by means of iron bars, through the holes 7c l m.

This roasting-furnace differs from those formerlyA in use in, (and this I consider the most important,-

part of my inventiom) that the shaft is higher and more conical inshape; that the gas is let in so low that the roasted ore can be taken out directly, through the openings situated immediately below the gas-pipes, v

and that the ore is accessible from all points through the large working-holes k, l, and jm, that are widening inward; that gas and air can be more effectually regulated, and that, as the roasting-process goes on only along the walls of thefuruace, the size of the furn'ac can be increased in proportion to the quantity of o which it is desired to produce. By these means, it is possible rto heat the ore up to melting-heat without danger of its baking and congealf.

ing before it can be withdrawn from the furnace. I am thereby also enabled to llengthen or shorten,

and, consequently, to determine with nicety the time for exposing the ore to the highest temperature, and

v ply of atmospheric air, the following advantages are gained:

First, that such deleterious ingredients as sulphur, arsenic, 85e., which render the produce'less good in quality, are separated from it.'

Second, that the ore is prepared for the process in the blast-furnace, so that it becomes more easy to reduce. l

Third, that the iron is thoroughly extracted from the ore, yielding thus a higher percentage with less consumption of coal. v

This method renders it, therefore, possible to employ ores which, in consequence of their deleterious-ingredients, could otherwise not have been employed under other circumstances, or would have yielded an inferior produce; but even for ores of good quality it has been found advantageous, at least in Sweden, to employ the same method, because the economical result has thereby been improved in every way.

By modifying the gas, the blast, the draught,'and y the labor, the temperature, as well as the time for roasting the ore, can be increased or diminished, according to its different chemical as well as physical properties.

By employing gas from the blast-furnace, the cost of the fuel is but nominal; but, if the supply of gas should already have been exhausted for other purposes, then other fuel can be used for the production of gas inra suitable common gas-generator. Y

In the same manner as the chimney can be builtin' different ways, as seen gby the di'erent constructions in the drawing, so alsoall the other parts of the furnace can be constructed of l various materials, such as plates, bricks, slag, Sac., which does not in any way alter the principle itself.

These furnaces can be built of various dimensions, to suitthe productive capacity of' the blast-furnaces which they are intended to provide with ore. 4.Ihe only difference is the diameter ofthe furnace, and the number of holes or openings.

Having thus described my invention,

I claim as new, and desire to secure by Letters Patentl. The application of the swinging shutter p to a roasting-furnace, when said shutter is automatically I opened by the ascending load of ore, substantially as herein shown and described.

2. The adjustable funnel c, when arranged in thel upright shaft of an ore-roasting furnace, substantially vas described, for the purpose of distributing the ore in any desired part of the furnace.

3. An upright ore-roasting furnace, A, when composed of the upright shaft A, mouth b, gas-supply pipes e e, air-supply pipes l1 h, working-apertures 7c l lm, and withdnming-apertures fi i, all arranged and operating substantially as herein shown and described.

Stockholm, June 3, 1868.

' ERNST WESTMAN.

Witnesses:

, GI F. BERUDns,

CARL VON BERGEN. 

